Alkylamidomethyl cellulose monoethers and process of making same



ALKYLomrHYr. CELLULOSE MONO- ETHERS AND PROCESS on MAKING SAME No Drawing. Application November 3, 1954 Serial No. 466,694

Claims. (Cl. 260-231) This invention relates to a new class of cellulose ethers and more particularly to alkylamidomethyl cellulose ethers and to a process for the preparation thereof.

The formation of durable finishes on cellulosic fabrics has been the object or" many investigations, most of which have sought to obtain durability by chemically linking the finishing agent to the cellulosic fabric, generally by ether and ester formations with the hydroxyl groups of the cellulose molecules. These durable finishes should be permanent as well as rendering the cellulosic fabric resistant to water, wrinkling and shrinking. The finishes must be applied without detrimental changes in other fabric properties such as tensile strength, crispness, abrasion resistance and hand.

This invention has as an object to provide a new class of alkylamidomethyl cellulose ethers. A further object is to provide cellulosic fabrics with durable finishes for' imparting water-repellency, flame-resistance and other properties. A still further object is to provide a process for the preparation of this new class of alkylamidomethyl cellulose ethers by a Michael-type addition of active hydrogen compounds to cellulose ethers containing an activated carbon to carbon double bond. Other objects will appear hereinafter.

These and other objects are accomplished by the following invention of cellulose ethers of the type wherein R is selected from the group consisting of hydrogen and lower alkyl radicals; R is selected from the group consisting of hydrogen and methyl radicals and X is the residue of an active hydrogen compound wherein the active hydrogen atom is linked to an atom selected from the group consisting of sulfur, nitrogen, phosphorus and oxygen and wherein the degree of substitution is between about 0.015 to 0.60. These cellulose ethers can be conveniently prepared by the reaction of cellulose ethers having the general formula The cellulose ethers containing an activated carbonto carbon double bond used as starting materials for the cellulose derivatives of the present invention are more particularly disclosed in my copending application Serial phites and alcohols.

. tion of benzyl mercaptan which proceeds in nearly quantir k t No. 466,699, filed of even date herewith and assigned to the assignee of the present invention. These cellulose ether starting materials are prepared by reacting cellulose with certain N-alkylol acrylamides in the presence of an acid catalyst.

The active hydrogen compounds useful in preparing the cellulose derivatives of the present invention include hydrogen sulphide, mercaptans, ammonia, amines, phos- Representative operable members of these groups of active hydrogen compounds are hydrogen sulphide, benzyl mercaptan and octadecyl mercaptan; ammonia, piperidine, octyl amine, morpholine, ethylene diamine, octadecylamines and commercial grades thereof and p-toluidine; diethyl phosphite, dibutyl phosphite and diphenyl phosphite; cellulose and aliphatic alcohols. The preferred active hydrogen compounds for purposes of the present invention are octadecyl mercaptan, octadecylamine and diethyl phosphite.

These active hydrogen compounds can be made to add to the activated carbon to carbon double bond of the cellulose ether by a Michael-type addition of active hydrogen compounds to a conjugated double bond, a wellknown reaction. The addition of the active hydrogen compound to the conjugated double bond in the present invention is efiected by suspending the cellulose ether containing the activated carbon to carbon double bond in a basic medium such as pyridine or aqueous alkali. This alkaline mixture is treated with the active hydrogen compound at temperatures between about 20 C. to C. for a few minutes to several hours. The reaction mixture is usually extracted hot with a series of organic solvents such as pyridine or benzene, then alcohol or acetone to remove unreacted active hydrogen compound, and finally water-washed and dried. The reaction time is not critical since the time generally required for good yields depends upon the degree of agitation, the temperature and the reactivity of the active hydrogen compound.

The preferred catalysts are pyridine and aqueous alkali. Usually the catalyst is employed as a solvent so that it is present in large amounts. In any event it is necessary to use enough catalyst so as to render the reaction medium basic.

The following examples will better illustrate the nature of the present invention; however, it is to be understood that the invention is not intended to be limited to these examples.

EXAMPLE I.Additi0n of cellulose hydroxyls to the' double bond of acrylamidomethyl cellulose ether When rayon challis fabric containing acrylamidomethyl groups (degree of substitution=0.12), which was pre pared by immersing a rayon challis at room. temperature in an aqueous pad bath solution which contained dissolved in it approximately 0.7% of ammonium chloride .(acid catalyst) and N-methylolacrylarnide in a concentration of 10%, was allowed to soak in 2% potassium hydroxide at room temperature, the cuprammonia-soluble cellulose derivative was rendered insoluble in less than 15 minutes. Microscopic examination showed that the insoluble fibers swelled .to about two to three times their original size and that the swelling was not appreciably reduced after about one hour total soaking in the KOH solution. Not all of the double bonds are utilized in cross-linking and some are available for reaction with active hydrogen compounds in aqueous solution.

The extent of this reaction after two hours in aqueous potassium hydroxide has been determined by the additative yield (Example II). I

3 4 Number acrylamidomethyl groups per hundred glucose in the presence of ammonium chloride from a 30% soluzmits tion of the amide in a 4:1 mixture of isopropanol and water, giving a final pick-up of about 6.5% after curing (dry wt., determined by weight gain). This fabric was Acrylamidomethylcgnulose 5:22;; 5 treated with octadecylmercaptan and diootadecylamine Ether Untreated Fabric Cellulose by the procedure of Example Ii, using 15% solutions in Ether pyridine. The surprisingly good durable water-repellency imparted by relatively small numbers of long-chain sub- By 2 53 3;, 3 gfiggitgg stituents on the cellulose is shown by the following table:

15 13 8 Percent of 23 19 13 Hydrophobic Spray test after- 30 27 18 Compound on Hydrophobic Compound (HX) Fabric As getevrvmingg 3ogrent $1921.12}

91g 8.0- as EXAMPLE u 15 Gain tion A variety of active hydrogen compounds in pyridine t d 1 a tan 1.01: 1.5 so so solutionwere heated as described below with the methylol 8s 33% figig g L5 8 2.0 80+ 80+ acrylamide treated rayon chalhs and with untreated rayon diootadecyl amine 0.1 to 0.5 80 70+ challis as controls. The extent of addition in all cases 20 was determined by weight gain and in some cases was EXAMPLE IV checked by analyses of the products for nitrogen, sulfur or phosphorus, depending on the nature of the adduct. The acrylanlldomeihyl Cellulcse i Was ShQWB The general equation for these reactions can be repret0 add arpmoma and y p Sulfide y m d b sulfide) in aqueous solution. The reactions proceeded readily at or near room temperature with concentrated 6 g E 6 Z CH X aqueous ammonium hydroxide and 12% sodium hydro- Ce 2* 2 2 sulfide solution as the sources of NH and H 8, respecwhere HX is an active hydrogen compound. The retively.

Degree of Substitution by Extent of Active Hydrogen Addition, Compound (HX) percent OHNHCOCH=OH1 CH2NHCOCH2CH2X hydrogen su1fide 0.10 0. 100 ammonia 0. 31 0. 22 71 actions, with the exception of the hydrogen sulfide and piperidine additions were conducted at the temperature of boiling pyridine for l to 24 hours (as indicated below). All the active hydrogen compounds in pyridine were used as to solutions. After treatment, the fabrics were boiled with at least 3 portions of fresh pyridine, several portions of acetone and finally rinsed several times in water. Weight gains were determined on bone dry samples (dried at 110 C. for 1% hours). The data so obtained are summarized in the following table. They include corrections for changes in weight of control samples. The degrees of substitution were calculated from The reaction described in Example II with benzyl mercaptan was conducted in the sauna way using methacrylamidomethyl cellulose ether under conditions where the.

addition of benzylmercaptan to acrylamidomethyl cellulose is nearly quantitative, it is only about 20 to complete with methacrylamido derivative.

EXAMPLE vr weight gains. The values in parentheses are degrees of The reaction with benzyl mercaptan described in Exsubstitutlon calculated from elemental analyses. ample II was conducted on a fabric contaimng N-meth- Active Hydrogen Com- Degree of Substitution By Degree of Substitution By Extent 01 pound (HX) Acrylamidomethyl Group Reaction Time (Hrs) -012h-NH-CO-CH2-OH2X Addition,

CH2NHOOGH2=OH1 Group percent hydrogensulfide (bubbled in) 0.11 1 (at reflux) then 20 0.11 (.08) 100 (at: room temp). benzyl mercaptan 0.11 2.5 0.11 09) 100 Do 0.32 0.24 (0.25) 75 oetadecyl mercaptan 0. 13 0.010 7. 7 dioctadecy1+dihexadecyl 0. 32 0.022 6.9

81111195. diethyl phosphite 0. 31 0.059 19 piperidine (no pyridine) 0.15 0. 080 53 The fabrics containing chemically linked dioctadecylamine and octadecyl sulfide groups are water repellent (spray ratings of 80) and the effect is not lost by boiling successively with pyridine, benzene, chloroform and ethanol. No reduction in spray rating was noted after a wash with aqueous solutions of sodium lauryl sulfate and of tallow soap plus sodium bicarbonate.

EXAMPLE III Methylolacrylamide was padded onto rayon challis ylacrylamidomethyl groups, with a low degree of substitution (0.025). The reaction proceeded as in the previous cases to give a benzyl sulfide cellulose derivative.

It is apparent from the preceding description that a variety of active hydrogen compounds can be made to add to the double bond of a cellulose ether containing an activated carbon to carbon double bond in a basic medium such as pyridine or aqueous alkali. When using aqueous alkali the active hydrogen compound must be a quite active one such as hydrogen sulfide or benzyl mercaptan to compete successfully against addition of free hydroxyl groups of the cellulose derivative to the olefinic double bonds of the substituents on the other cellulose hydroxyls. When the free hydroxyls add to the olefinic double bonds, a cross-linked product is obtained, as described in Example I, which exhibits a reduced solubility in cuprammonium hydroxide. Generally a crosslinked product tends to provide more durability and improved crease resistance.

When diethyl phosphite is used as the active hydrogen compound an addition to the olefinic double bond takes place as well as an ester exchange with the free hydroxyl groups of the cellulose When using short reaction times most of the diethyl phosphite adds to the double bond; however, with longer refluxing periods, both types of re action occur, i. e., addition to the double bond and ester exchange with tree hydroxyls.

The cellulose used to form the cellulose ethers containing the activated carbon to carbon double bond and subsequently the products of the present invention may be in the form of cotton fibers, threads or woven fabric.

The cellulose ethers of the present invention exhibit improved water-repellency, flame-resistance, wrinkling and shrinking properties. The finish imparted to the cellulosic fabric is durable without any detrimental change in other fabric properties such as tensile strength, crispness, abrasion resistance and hand.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments thereof except as defined in the appended claims.

What is claimed is:

l. A cellulose ether of the general type wherein the degree of substitution is between about 0.015 to 0.60.

3. A cellulose ether of the type wherein the degree of substitution is between about 0.015

4. A cellulose ether of the type wherein the degree of substitution is between about 0.015

5. A process for the preparation of cellulose ethers which comprises reacting a cellulose derivative having the general formula II ce11-o-oH,-NR-o-o1t'=oH, wherein R is a radical selected from the group consisting of hydrogen and lower alkyl radicals of 1 to 4 carbon atoms and R is a radical selected from the group. consisting of hydrogen and methyl radicals and wherein the degree of substitution is between about 0.015 to 0.60, with an active hydrogen compound wherein the active hydrogen atom is linked to an atom selected from the group consisting of sulfur, nitrogen, phosphorus and oxygen, in a basic medium at a temperature of about 20 C. to 120 C. and separating the cellulose ether thus produced.

6. A process for the preparation of a cellulose ether which comprises reacting a cellulose derivative having the formula wherein the degree of substitution is between about 0.015

to 0.60 with diethyl phosphite in the presence of pyridine at a temperature of about C. and separating the cellulose ether thus produced.

7. A process for the preparation of a cellulose ether which comprises reacting a cellulose derivative having the formula 7 o cel1OOH NH-( iQH=GH, wherein the degree of substitution is between about 0.015 to 0.60 with octadecyl mercaptan in the presence of pyridine at a temperature of about 115 C. and separating the cellulose ether thus produced. I

8. A process for the preparation of a cellulose ether which comprises reacting a cellulose derivative having the formula wherein the degree of substitution is between about 0.015 to 0.60 with octadecyl amine in the presence of pyridine at a temperature of about 115 C. and separating the cellulose ether thus produced.

9. A process for the preparation of a cellulose ether which comprises reacting cellulose derivatives having the formula O ce1l-OOHg-NH-( CH=GHa wherein the degree of substitution is between 0.015 to 0.60 with ammonia in the presence of pyridine at a temperature of about 115 C. and separating the cellulose ether thus produced.

wherein'the'degree of substitution is between about 0.015

References Cited in the file of this-patent -UNITED STATES PATENTS 2,317,75 6

Graenacker et al. Apr. 7, 1943 2,384,888 Burke Sept. 18, 1945 2,388,597 Burke Nov. 6, 1945 2,399,603 Russ et al Apr. 30, 1946 2,455,083 Musser Nov. 30, 1948 

1. A CELLULOSE ETHER OF THE GENERAL TYPE
 5. A PROCESS FOR THE PREPARATION OF CELLULOSE ETHERS WHICH COMPRISES REACTING A CELLULOSE DERIVATIVE HAVING THE GENERAL FORMULA. 